Holaa!, like Truecaller, allows users to see details like the caller's name, photo and location during an incoming call live. It also helps block spam calls from pesky spammers or other unwanted callers.

"On an average, 4 out of 10 calls on pre-paid mobile numbers are from unknown numbers, while 1 out of these 4 unknown calls is a spam call," Nimbuzz India CEO Vikas Saxena said.

This makes it one of the mass market needs on smartphones today and Holaa! will be of immense help to users, he added.

India is one of the largest markets for Stockholm-based Truecaller. About 40 million of its userbase and almost half of new additions (over 200,000 new users join daily) are from India. Globally, it has more than 85 million users.

"We already have half a million downloads of the app and we are hopeful of hitting the million mark in the next few weeks. We are aiming for 10 million users," Saxena said.

Holaa! is available in English, French, Spanish, Arabic, Persian and Portuguese on Android devices.

"Holaa! has been developed completely in India by a team of 13 young developers and reflects the confidence we have in the potential of the market here. Nimbuzz's technologies will be a key part of our vision of an integrated 'my digital life' ecosystem," New Call Telecom CEO Nigel Eastwood said.